Conventional electric motors are each provided with an electric-power control device which controls driving of a motor main body including a rotor, a stator, etc. The electric-power control device includes a substrate on which a power IC, a microcomputer, etc., are mounted. As the substrate, for example, an annular substrate having a through hole is adopted, the through hole being formed to allow, for example, a rotation shaft of the rotor, to pass through the through hole (see, for example, Patent Literature 1).